Project Summary/Abstract Complex relationships exist between mental illness and aggression, particularly interpersonal aggression that can lead to antisocial behavior. Unfortunately, conducting high-impact mental health research among those who have committed serious aggressive acts against persons has been strategically challenging for many reasons. This research plan employs unique resources that enable advanced cognitive neuroscience research to be conducted in forensic environments. Here we leverage these resources to examine impaired functioning of neural circuits that contribute to specific varieties of serious aggressive behavior. Callous and unemotional traits, impulsive/disinhibited behavior, and appetitive desire to harm others, all have identifiable roots in neurocognitive function. We will examine how clinical levels of these latter traits are related to abnormalities in the neural circuits involved in affective perspective taking, moral decision-making, and behavioral inhibition. Normative neural responses for each of these processes have been well-characterized by our prior work. We seek to differentiate between unique pathophysiological etiologies that contribute to specific behavioral tendencies. We further aim to elucidate the modifying influence of early childhood trauma in these neurocognitive domains. Understanding these differences will promote more sophisticated prevention and intervention strategies that incorporate specific knowledge of neurocognitive vulnerabilities and remedial approaches for improving long-range outcomes for individuals and for the public.